Jacoby also tweeted that his 10-year-old son, Micah, has been praying for his older brother’s return.

“Our 10-yr-old, Micah, has been reciting Psalm 121 each morning & night since his big brother Caleb went missing,” the tweet read.

The Psalm, which begins: “I lift my eyes up to the hills where does my help come from? My help comes from the Lord…,” ends with: “The Lord will watch over your coming and going both now and forevermore.”

Caleb Jacoby, 16, has been missing since midday on Jan. 6. Police believe Caleb, an 11th-grader at the Maimonides School in suburban Boston, may be a runaway.

ABC6 in Providence reported Wednesday afternoon that there had been “several reports” placing the teen in Providence on Tuesday evening, but police said they reviewed tape from the sighting and do not believe it is credible, according to CBS Boston.

“It’s the worst nightmare that any parent can ever live through and we’re hoping and praying that the nightmare will end with something good to come home with,” Rabbi Gershon Gerwirtz, who is close to the Jacoby family, told CBS Boston.

Some 200 volunteers, including friends and neighbors of the family as well as members of local Jewish groups, searched throughout the Boston area in a coordinated effort on Wednesday. The effort was spearheaded by the Maimonides School.

“Thank you to the hundreds of volunteers from the entire community who participated in the ongoing search for Caleb Jacoby today. We are deeply grateful for this outpouring of support,” the school posted on its Facebook page. “We will continue to support the outstanding efforts of the Brookline Police Department, and provide updates with new information as appropriate. We continue to pray for Caleb’s safe return.”

Caleb’s photo has been circulated on Facebook and Twitter.

“We are so deeply, deeply grateful for everything being done to reunite us with our beloved son Caleb,” Jeff Jacoby, who is Jewish and often writes on Jewish and Israel issues in his column, tweeted late Tuesday night.

For many years, near his oldest son’s birthday, Jacoby wrote a special column called “Letters to Caleb.”